Legal Question in Family Law in California

Support does not, by definition, cover shelter. Child support does not cover any particular expenses in California. It is a form of equalizing payment that only takes into account each parent's income (or in some cases attributed income, such as for those lucky enough to be living off an inheritance or something, or those chosing not to work who could), the custodial time with each parent, and certain limited deductions. Those are then fed into a court approved software program, DissoMaster being by far the most common, and it spits out a support payment to the spouse with the lower income and/or more time with the kids.

IF you no longer own any interest in the house, AND you are not on the loan yourself, in other words if the debt is hers alone AND you are not benefitting from making the payment because you still are on title to the house, you MIGHT persuade a court to count that as an offset against your support payments due. Generally, though, even then the court would tell you to pay her and let her pay her own debts. If it's a joint debt, and/or you haven't settled property so the house is still community property, or if you have given her the house but retained a "pay on sale" or similar interest in it to get your share out later, forget calling that payment any kind of set off against support.

The only good news is that if the property division isn't settled yet, and you are making payments, she MAY owe some contribution back to the community property "pile" for the rental value of the home.